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Old 27-03-2012, 05:43 PM
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alistairsam
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Join Date: Nov 2009
Location: Box Hill North, Vic
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Do I need to adjust the phd setting min motion depending on the image scale of the main scope and guide scope to reduce field rotation.

here are the calculations I've come up with using CCD Calculator

Imaging Scope & Imaging Camera

8" F4/QHY8
Pixel size - 7.8um x 7.8um
Array Size - 3032 x 2016
Chip Size - 15.7 x 23.6mm
Image Scale - 2.01 arcsec/pix
FOV - 67.5 x 101.5 arcmin

Guider Image scale

80mm F5 ST80 / QHY5
Pixel size - 5.2um x 5.2um
Array Size - 1280 x 1024
Chip Size - 5.3 x 6.7mm
Image Scale - 2.68 arcsec/pix
FOV - 45.7 x 57.1 arcmin

So would this mean a movement of 0.75 pixels of the imaging scope causes a 1 pixel movement of the guidescope or vice versa?
so would a min motion setting of 0.75 pixels in phd (2.01/2.68) be correct?
I know there's only one way to test it, but its clouded up as usual.
This is driving me nuts to say the least.
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